Apparatus for separating oil and solids from water

ABSTRACT

The present invention relates to improved apparatus for separating oil and solids from a stream of water. A closed vessel is provided having a first vertical partition disposed therein dividing the vessel into first and second compartments. A second vertical partition is disposed within the lower portion of the first compartment dividing it into two separate filter areas and a filter bed is disposed in each of the filter areas. An inlet water connection is provided extending to within the first compartment, and a pair of slotted inlet water distribution conduits are disposed in the first compartment, each positioned horizontally within a filter area centrally above a filter bed. The slotted water distribution conduits are connected together and to the inlet water connection. Means for removing separated oil from the first compartment are provided therein and a pair of filtered water outlet connections are provided, each disposed in a filter area below a filter bed. Filtered water inlet and outlet connections are disposed in the bottom portion of the second compartment, and conduit means for conducting filtered water between the first compartment and the second compartment are connected to the first compartment filtered water outlet connections and the second compartment filtered water inlet connection. A backwash pump is connected to the conduit means and valve means are provided in the conduit means for controlling the flow of filtered water from the first compartment to the second compartment, and the flow of backwash water from the second compartment separately to the filter areas of the first compartment.

United States Patent [191 Barra et al.

3,784,010 Jan. 8, 1974 APPARATUS FOR SEPARATING OIL AND SOLIDS FROMWATER Inventors: Frank J. Barra, Midwest City,

Okla; Kenneth R. Murrell, Odessa, Tex.

Assignee:

[73] Black, Sivalls & Bryson, Inc.,

Oklahoma City, Okla. 221 Filed: Aug. 23, 1972 [21] Appl. No.: 283,180

[52] U.S. Cl 210/114, 210/115, 210/128,

210/264, 210/277 [51] Int. Cl B01d 23/26 [58] Field of Search PrimaryExaminer-John Adee l-lessin 8E Dougherty [57] ABSTRACT The presentinvention relates to improved apparatus tafieparann oil and solids froma stream of water. A closed vessel is provided having a first verticalpartition disposed therein dividing the vessel into first and secondcompartments. A second vertical partition is disposed within the lowerportion of the first compartment dividing it into two separate filterareas and a filter bed is disposed in each of the filter areas. An inletwater connection is provided extending to within the first compartment,and a pair of slotted inlet water distribution conduits are disposed inthe first compartment, each positioned horizontally within a filter areacentrally above a filter bed. The slotted water distribution conduitsare connected together and to the inlet water connection. Means forremoving separated oil from the first compartment are provided thereinand a pair of filtered water outlet connections are provided, eachdisposed in a filter area below a filter bed. Filtered water inlet andoutlet connections are disposed in the bottom portion of the secondcompartment, and conduit means for conducting filtered water between thefirst compartment and the second compartment are connected to the firstcompartment filtered water outlet connections and the second compartmentfiltered water inlet connection. A backwash pump is connected to theconduit means and valve means are provided in the conduit means forcontrolling the flow of filtered water from the first compartment to thesecond compartment, and the flow of backwash water from the secondcompartment separately to the filter areas of the first compartment.

5 Claims, 3 Drawing Figures 551 A FA 750 70 DP/i/A/ APPARATUS FORSEPARATING OIL AND SOLIDS FROM WATER BACKGROUND OF THE INVENTION 1.Field of the Invention The present invention relates to improvedapparatus for separating oil and solids from water, and moreparticularly, but not by way of limitation, to improved apparatus forfiltering a stream of water containing oilcoated solids so that the oiland solids are removed from the water and the oil is recovered.

2. Description of the Prior Art Many various types and kinds of waterfilters have been developed and used successfully for removing solidparticles from water and other liquids. A particular water filteringproblem encountered in the production of oil wells is the treatment ofproduced water to remove entrained oil and oil-coated solids therefrom.After separation of produced oil and water in conventional separationapparatus, the water must be disposed of in a suitable manner. Often,this is accomplished by pumping the water into a disposal well, and inorder to prevent plugging of the disposal well formation by oil coatedsolids entrained in the water and the waste of the oil carried with thewater, the water must be treated for the removal of the solids and oilprior to injection.

This type of water filtering problem is particularly acute in waterflood operations where large volumes of water are pumped into producingformations to increase the oil productivity thereof. The water recoveredwith the produced oil is separated and recycled to the producingformation, and in order to efficiently recover the oil produced andremove solids from the water so that formation plugging does not occur,the water must be treated prior to injection into the formation.

It has heretofore been the practice to pass a stream of water containingoil and oil-coated solids through a vessel containing a filter bed forremoving the solid particles and coalescing the oil from the water.Periodically, the filter bed utilized must be backwashed in order toremove accumulated solids therefrom and restore the filteringeffectiveness thereto. So that a relatively small backwash pump may beemployed, the filter vessel may include provision for backwashing thefilter bed in portions. That is, separate portions of the filter bed maybe sequentially backwashed thereby maintaining the velocity of flowrequired for the effective removal of solid material without thenecessity'of a very large backwash pump and expense involved in theinstallation and operation thereof.

By the present invention, improved apparatus for efficiently andeconomically separating oil and solids from water is provided whichincludes provision for backwashing the filter bed in portions and whichincludes a filtered water accumulator and source of backwash waterwithin a unitary vessel.

SUMMARY OF THE INVENTION The present invention relates to improvedapparatus for separating oil and solids from water which comprises aclosed vessel having a first vertical partition disposed thereindividing the vessel into first and second compartments. A secondvertical partition is disposed within the lower portion of the firstcompartment thereby dividing the first compartment into two separatefilter areas, and a filter bed is disposed in each of the filter areas.An inlet water conduit is provided extending within the firstcompartment, and a pair of slotted water distribution conduits aredisposed in the first compartment, each positioned horizontally within afilter area above a filter bed. The slotted inlet water distributionconduits are connected together and to the inlet water conduit. A pairof filtered water outlet connections are provided, each disposed in afilter area below a filter bed, and filtered water inlet and outletconnections are disposed in the bottom portion of the secondcompartment. Conduit means for conducting filtered water between thefirst compartment and the second compartment are connected to the firstcompartment filtered water outlet connections and the second compartmentfiltered water inlet connection. A backwash pump is connected to theconduit means and valve means are disposed in the conduit means for controlling the flow of filtered water from the first compartment to thesecond compartment and the flow of backwash water from the secondcompartment separately to the filter areas of the first compartment,through the filter beds and out of the first compartment by way of theslotted inlet water distribution conduits. It is, therefore, an objectof the present invention to provide an improved apparatus forefficiently and economically separating oil and solids from water.

A further object of the present invention is to provide an improvedapparatus for removing oil and solids from a stream of water wherein thebackwash of the filter beds may be carried out simply and economically.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view ofthe improved apparatus of the present invention in cross section,

FIG. 2 is a cross sectional view taken along lines 2-2 of FIG. 1, and

FIG. 3 is a cross sectional view taken along lines 3-3 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,and particularly to FIG. 1, the improved apparatus of the presentinvention isillustrated and generally designated by the numeral 10. Theapparatus 10 is comprised of a closed horizontal vessel 12 having avertical partition 14 disposed therein which divides the vessel into afirst compartment 16 and a second compartment 18. As shown best in FIG.3, the vertical partition 14 is seal welded to the inside periphery ofthe vessel 12 except for the uppermost position thereof which terminatesa short distance below the top of the vessel 12. The resulting opening15 between the partition 14 and the top of the vessel 12 provides apassageway for removing oil from':

the first compartment 16 as will be further described herein.

A second vertical partition 20 is disposed within the first compartment16 of the vessel 10 positioned on a line coinciding with the axis of thevessel 10. Thesides and bottom of the partition 20 are seal welded tothe partition 14 and to the end and bottom of the vessel 12. The topedge of the partition 20 is horizontal and terminates a short distanceabove the axis of the vessel 12 so that a pair of separate filter areas22 and 24 (FIGS. 2 and 3) are formed in the first compartment 16. v

Beds of filter media 26 and 28 are provided in the filter areas 22 and24 respectively, formed of a suitable filtering material such as sand,ground anthracite coal, etc. As will be understood by those skilled inthe art, horizontal perforated gratings or other conventional filter bedsupports 30 and 32 are provided in the lower portions of the filterareas 22 and 24 respectively, for supporting the filter beds 26 and 28within the vessel 12.

An inlet water connection 34 is provided extending into the firstcompartment 16 of the vessel 12. A pair of slotted water distributionconduits 36 and 38 are disposed within the filter areas 22 and 24centrally above the filter beds 26 and 28. Each of the waterdistribution conduits 36 and 38 are connected to a connector pipe 40which is in turn connected to the inlet water connection 34. The inletwater connection 34, connector pipe 40 and slotted inlet waterdistribution pipes 36 and 38 are all positioned in a horizontal plane adistance below the top edge of the vertical partition 20. As can be bestseen in FIG. 1, the slots formed in the distribution conduits 36 and 38are positioned on a line and. face upwardly. A pair of inverted V-shapeddeflector plates 42 and 44 are positioned a short distance above theslotted distribution conduits 36 and 38. As will be described furtherhereinbelow, the deflector plates 42 and 44 are positioned with respectto the distribution conduits 36 and 38 so that inlet water flowingthrough the slots of the conduits 36 and 38 is caused to flow upwardly,impinge on the deflectors 42 and 44 and then flow downwardly through thefilter beds 26 and 28.

A pair of filtered water outlet connections 46 and 48 are provided inthe first compartment 16 of the vessel 12 below the filter beds 26 and28 respectively. A filtered water inlet connection 50 is provided in thebottom portion of the vessel 12 in the second compartment 18. A filteredwater outlet connection 52 for removing filtered water from the secondcompartment 18 is provided in the lower portion of the vessel 12 and anoil outlet 54 for removing separated oil from the second compartment 18is provided in the top portion of the vessel 12. As best shown in FIGS.1 and 3, the filtered water outlet connections 46 and 48are connected bya pair of conduits 56 and 58 to a conduit 60 which is in turn connectedto filtered water inlet connection 50. A pair of conventional shutoffvalves 62 and 64 are disposed in the conduits 56 and 58 respectively,and a shutoff valve 66 is disposed in the conduit 60. A conventionalbackwash pump 68 is provided connected to the conduit 60 by conduits 70and 74 having shutoff valves 72 and 76 disposed therein respectively. I

The inlet water connection 34 is connected to the source of water to betreated by a conduit 80. A shutoff valve 82 is disposed in the conduit80 and a conduit 84 for removing backwash water from the apparatus isconnected to the conduit 80 between the valve 82 and the inlet waterconnection 34. A shutoff valve 86 is provided in the conduit 84.

OPERATION OF THE APPARATUS 10 In operation of the apparatus l0,a streamof water containing entrained oil and oil-coated solid material isflowed by way of conduit 80 and valve 82 to the inlet water connection34 of the apparatus 10. The valve 86 disposed in the backwash wateroutlet conduit 84 is closed until such time as the filter beds 26 and 28are backwashed.

The inlet water passes through the inlet water connection 34 and theconnector pipe 40 into the slotted water distribution conduits 36 and38. As will be understood, the stream of inlet water is divided into twostreams which flow through the slots disposed in the conduits 36 and 38in an upward direction into contact with the deflector plates 42 and 44respectively. The upwardly flowing water impinges on the inverted V-shaped deflector plates 42 and 44 and the direction of the water ischanged so that it flows downwardly towards the filter beds 26 and 28respectively. Due to the change in direction of the inlet water as itpasses from the slotted inlet water distribution conduits 36 and 38 tothe filterbeds 26 and 28, entrained oil carried in the wateragglomerates on the deflector plates 42 and 44 and gravitates upwardlyfrom the deflector plates into a body of oil 90 maintained in the topportion of the compartment 16 of the vessel 12.

The vessel 12 is operated in a flooded manner, i.e., the vessel 12 iscompletely filled with liquid. Due to the lighter density of oil ascompared to water, it gravitates upwardly within the vessel 12 and anoil-water interface is formed. That is, an oil-water interface 92 isformed within the first compartment 16 of the vessel 12 between the bodyofoil 90 in the upper portion thereof and a body of water 94 in thelower portion thereof. The separated oil accumulating in the firstcompartment 16 may be removed by providing an oil outlet connection inthe top portion of the vessel 12 extending to within the compartment 16.If this arrangement is utilized, the partition 14 extends to the top ofthe vessel 12 forming a fluid tight seal between the first compartment16 and the second compartment 18. However, in order to retain theseparated oil within the vessel 12 for as long a time period aspossiblethereby insuring complete separation of the oil from the water, thearrangement illustrated in the drawings and described above whereby apassageway 15 is formed between the top portions of the compartments l6and 18 is utilized. In operation of this embodiment of the apparatus 10,oil accumulating in the body 90 thereof within. the compartment 16passes through the passageway 15 into the top portion of the compartment18 forming a body of oil within the compartment 18. An oil-waterinterface 102 is formed in the compartment 18 between the body of oil100 and a body of water 104 maintained within the compartment 18.

After being discharged within the filter areas 22 and 23 of the firstcompartment 16, the inlet water containing entrained oil-coated solidspasses downwardly through the filter beds 26 and 28. As the waterpasses. through the filter beds 26 and 28, the solid material settlesonto the filter beds and is removed from the water. The clean filteredwater passes out of the first compartment 16 of the vessel 12 by way ofthe outlet connections 46 and 48. The oil coating on the solid materialtrapped on the filter beds agglomerates into drops and gravitatesupwardly into the body of oil 90 in the compartment 16 and the body ofoil 100 in the compartment 18. The filtered water from the firstcompartment 16 passes through the conduits 56 and 58, valves 62 and 64,the conduit 60, and the valve 66 into the compartment 18 by way of theinlet connection 50. A float operated level controller assembly 106 isprovided attached to the vessel 12 for automatically controlling thedischarge of water and oil from the compartment 18. That is, the liquidlevel control device 106 senses the level of the oil-water interface 102by means of an interface float 108. A control valve 110 is disposed inthe conduit 112 connected to the water outlet connection 52. The controlvalve 110 is operably connected to the level control device 106 and isopened and closed automatically in accordance with the level of theinterface 102 within the compartment 18. That is, as the interface 102rises, the valve 110 is opened to allow more water to escape from thebody 104 thereof thereby lowering the interface. As the interface 102lowers, the valve 110 is closed thereby forcing oil from the body 100thereof out the outlet connection 54 by way of outlet conduit 114. Apressure controlled valve 116 is provided disposed in a conduit 114attached to the oil outlet connection 54. As will be understood, whenthe valve 110 is closed the pressure within the vessel 12 increasescausing the pressure control valve 116 to open and oil to be dischargedfrom the vessel 12. Periodically during the operation of the apparatus10, the filter beds 26 and 28 become loaded with solids removed from thewater passing therethrough, which solids must be removed in order toprevent clogging of the filter beds. in the operation of the apparatusto bring about the quick and efficient backwashing of the filter beds 26and 28, the flow of inlet water is shut off to the apparatus 10 byclosing the shutoff valve 82 and the valve 86 is opened. The vessel 12is then isolated by closing appropriate shutoff valves (not shown). Oneof the valves 62 and 64 is closed, the valve 66 is closed, and thevalves 72 and 76 are opened. The backwash pump 68 is then started sothat filtered water is drawn from the compartment 18 of the vessel 12 byway of the conduit 60 and the conduit 74 into the backwash pump 68. Thebackwash water is discharged from the pump 68 into the compartment 16 ofthe vessel 12 by way of the conduit 70, the valve 72, one of theconduits 56 or 58 and one of the valves 62 or 64. Assuming that thefilter area 22 is backwashed first, the backwash water flows by way ofconduit 56, valve 62 and the connec tion 46 upwardly through the filterbed 26. The backwash water accumulates in the filter area 22 until alevel is reached such that the backwash flows into the waterdistribution conduit 36 by way of the slots contained therein. Thebackwash water and removed solids then pass from the filter bed 26 byway of the conduit 36 and connection 34 into the conduit 84. As will beunderstood, the partition which terminates at a level above the conduits36 and 38 prevents backwash water and solid material from spilling intothe filter area 24 while the filter area 22 is being backwashed and viceversa. Once the backwashing of the filter bed 26 is completed, valve 62is closed and valve 64 is opened so that the filter bed 28 within thefilter area 24 is backwashed in an identical manner. Because the filterbeds within the compartment 16 may be backwashed in two portions orparts, the backwash pump 68 may be relatively small and inexpensive tooperate. Once the backwashing operation has been completed appropriatevalves are closed and opened so that normal flow of water and oilthrough the apparatus 10 is restarted.

Thus, by the present invention an improved apparatus for separating oiland solids from water is provided which is economical to install andoperate as compared to prior art apparatus and which is well adapted tocarry out the objects and attain the ends and advantages mentionedherein. While presently preferred embodiments of the invention are givenfor the purpose of disclosure, numerous changes in detail of theconstruction and arrangement of parts can be made which will readilysuggest themselves to those skilled in the art and which are encompassedwithin the spirit of the invention disclosed herein.

What is claimed is:

1. Apparatus for separating oil and solids from water which comprises: I

a closed vessel;

a first vertical partition disposed within said vessel dividing saidvessel into first and second compartments;

a second vertical partition disposed within the lower portion of saidfirst compartment dividing said first compartment into two separatefilter areas;

a horizontal filter bed disposed in each of said filter areas;

an inlet water conduit connected through a wall of said vessel andextending within said first compartment;

a pair of slotted inlet water distribution conduits each positionedhorizontally within one of said filter areas above one of said filterbeds, said slotted inlet water distribution conduits being connectedtogether and to said inlet water conduit;

a pair of filtered water outlet connections, each disposed in one ofsaid filter areas below said filter beds;

means for removing separated oil from the top portion of said firstcompartment and from said vessel;

filtered water inlet and outlet connections disposed in the bottomportion of said second compartment;

conduit means for conducting filtered water between said firstcompartment filter areas and said second compartment connected to saidfirst compartment filtered water outlet connections and said secondcompartment filtered water inlet connection;

a backwash water pump connected to said conduit means; and

valve means disposed in said conduit means and connected to said inletwater conduit for controlling the fiow of filtered water from said firstcompartment to said second compartment and the flow of backwash waterfrom said second compartment separately to said filter areas of saidfirst compartment, through one of said filter beds and out of said firstcompartment and said vessel by way of one of said slotted inlet waterdistribution conduits and said inlet water conduit.

2. The apparatus of claim 1 which is further characterized to includelevel control means for controlling the level of filtered water in saidsecond compartment attached to said vessel.

3. The apparatus of claim 2 wherein said means for removing theseparated oil from the top portion of said first compartment and fromsaid vessel comprises an oil outlet connection disposed in the topportion of said first compartment.

4. The apparatus of claim 2 wherein said means for removing separatedoil from the top portion of said first compartment and from said vesselcomprises:

an oil overflow passageway comunicating said first and secondcompartments; and

an oil outlet connection disposed in the top portion of said secondcompartment.

5. The apparatus of claim 3 which is further characa pair of elongatedinverted V-shaped deflector terized to include: plates disposed withinsaid first compartment each each of said slotted inlet waterdistribution conduits positioned parallel to the slots of and above oneof including slots formed on a line along a length said slottedconduits. thereof and positioned facing upwardly; and

1. Apparatus for separating oil and solids from water which comprises: aclosed vessel; a first vertical partition disposed within said vesseldividing said vessel into first and second compartments; a secondvertical partition disposed within the lower portion of said firstcompartmEnt dividing said first compartment into two separate filterareas; a horizontal filter bed disposed in each of said filter areas; aninlet water conduit connected through a wall of said vessel andextending within said first compartment; a pair of slotted inlet waterdistribution conduits each positioned horizontally within one of saidfilter areas above one of said filter beds, said slotted inlet waterdistribution conduits being connected together and to said inlet waterconduit; a pair of filtered water outlet connections, each disposed inone of said filter areas below said filter beds; means for removingseparated oil from the top portion of said first compartment and fromsaid vessel; filtered water inlet and outlet connections disposed in thebottom portion of said second compartment; conduit means for conductingfiltered water between said first compartment filter areas and saidsecond compartment connected to said first compartment filtered wateroutlet connections and said second compartment filtered water inletconnection; a backwash water pump connected to said conduit means; andvalve means disposed in said conduit means and connected to said inletwater conduit for controlling the flow of filtered water from said firstcompartment to said second compartment and the flow of backwash waterfrom said second compartment separately to said filter areas of saidfirst compartment, through one of said filter beds and out of said firstcompartment and said vessel by way of one of said slotted inlet waterdistribution conduits and said inlet water conduit.
 2. The apparatus ofclaim 1 which is further characterized to include level control meansfor controlling the level of filtered water in said second compartmentattached to said vessel.
 3. The apparatus of claim 2 wherein said meansfor removing the separated oil from the top portion of said firstcompartment and from said vessel comprises an oil outlet connectiondisposed in the top portion of said first compartment.
 4. The apparatusof claim 2 wherein said means for removing separated oil from the topportion of said first compartment and from said vessel comprises: an oiloverflow passageway comunicating said first and second compartments; andan oil outlet connection disposed in the top portion of said secondcompartment.
 5. The apparatus of claim 3 which is further characterizedto include: each of said slotted inlet water distribution conduitsincluding slots formed on a line along a length thereof and positionedfacing upwardly; and a pair of elongated inverted V-shaped deflectorplates disposed within said first compartment each positioned parallelto the slots of and above one of said slotted conduits.